磁控溅射中电磁场分布及带电粒子运动的模拟与计算

电磁场分布及其对各种带电粒子的约束情况对磁控溅射过程有着决定性的影响。本文首先利用物理场耦合分析软件Comsol 3．2a分析了直流磁控溅射电磁场的分布，并且计算分析了单个带电粒子的运动情况。在此基础上，计算分析了带电粒子束流在电磁场中的运动情况、空间分布，得到了磁控溅射电磁场区域分布、单个电子的运动轨迹及带电粒子在空间区域中位置分布。     

直流磁控溅射中矩形平面靶刻蚀形貌的数值计算及优化

对普通矩形平面靶的磁场分布、电子运动轨迹和电子分布进行了理论计算。通过磁场的解析表达式,解出电子在磁场中的运动方程,求得并从理论上解释了电子的运动轨迹。由电子的运动轨迹,并运用Monte Carlo方法,求得电子在磁场中的分布,得到电子分布的均值和标准差。本文通过在基片和靶材间加正向电场,改变了电子的运动轨迹和空间分布,优化了矩形平面靶的刻蚀形貌,提高了靶材利用率。     

磁控溅射设备中铜靶刻蚀形貌的仿真计算研究

提出了一种铜靶刻蚀形貌模拟方法,基于靶材溅射率与靶材表面磁场水平分量成正比的假设,以美国应用材料公司的小行星PVD磁控溅射装置为算例,实现了复杂运动轨迹铜靶刻蚀形貌的模拟,仿真计算结果与实际设备中铜靶刻蚀形貌有较好的一致性,为通过磁场分布研究靶材刻蚀形貌提供了一种理论方法。     

直流磁控溅射中磁场强度和阴极电压对圆平面靶刻蚀形貌的影响

本文借助Comsol和Matlab软件模拟了直流磁控溅射圆平面靶系统的磁场分布和荷电粒子分布,对不同磁场强度和阴极电压条件下的荷电粒子分布进行了模拟分析,通过比较靶面离子流密度分布曲线发现:当磁场强度增强时,靶面离子流密度分布曲线会变得更加陡窄;当阴极电压变化时,靶面离子流密度分布曲线几乎没有变化.说明靶材的刻蚀形貌会随磁场强度增强而变窄,而阴极电压变化对靶材的刻蚀形貌没有影响.上述结论对直流磁控溅射工艺参数优化具有一定的理论指导意义.     

磁控溅射靶材刻蚀特性的模拟研究

靶材刻蚀特性是研究磁控溅射靶材利用率、薄膜生长速度和薄膜质量的关键因素.本文用有限元 分析软件ANSYS模拟了磁控溅射放电空间的磁场分布,用粒子模拟软件OOPIC Pro(object oriented particle in cell)模拟了放电过程,最后用SRIM(stopping and range of ions in matter)模拟了靶材的溅射特性,得到了靶材的刻蚀形貌和刻蚀速度,并讨论了不同工作气压和不同阴极电压对靶材刻蚀的影响.模拟结果表明:靶材刻蚀形貌与磁场分布有关,磁通密度越强,对应的靶材位置刻蚀越深;靶材的刻蚀速度随阴极电压的增大而增大,而当工作气压增大时,靶材的刻蚀速度先增大后趋向平衡,当工作气压超过一定的值时,刻蚀速度随气压的增大开始减小.模拟结果与实验观测进行了比较,二者符合较好.     

ICP刻蚀GaP表面形貌控制

不同角度的GaP表面形貌刻蚀主要依赖于刻蚀参数的调节以及光刻胶的形貌,但要得到能够重复的光刻胶形貌是很困难的.研究了如何通过调节感应耦合等离子（ICP）刻蚀仪器本身的参数,而不依赖于不定的光刻胶形貌来得到可重复的表面形貌.通过研究可知,射频功率与腔室压强是影响表面形貌的最重要的两个参数.射频功率越小刻蚀得到的角度越大,腔室压强越大刻蚀得到的角度也越大.通常BCl3等离子体被用来作为GaP的刻蚀气体,但为了维持所需的等离子浓度以及更大的操作压强,Ar被加入刻蚀气体中.     

外加磁场对磁控溅射靶利用率的影响

通过在基片上直接放置一块永久磁铁来研究外加磁场对磁控溅射靶利用率的影响。实验发现 ,外加磁场的引入改变了靶表面附近的磁场分布 ,因而靶的刻蚀环的位置、宽度和深度均发生了明显的变化 ,靶的利用率在S S构型和S N构型中均比无外加磁场时要高。利用空间模拟磁场成功的解释这一实验现象。在S S构型和S N构型中 ,后者靶的刻蚀深度轮廓线比较平坦 ,相对刻蚀深度值更大 ,更能有效地提高靶的利用率     

Ti-O薄膜的溅射刻蚀微形貌表面对内皮细胞生长的影响

利用磁控溅射合成具有一定特性的Ti-O薄膜,并采用Ar离子溅射刻蚀该薄膜表面.运用原子力显微镜(AFM),X射线衍射(XRD)对刻蚀后的薄膜表面微观形貌、微结构进行表征.结果表明薄膜的结构未发生变化,表面的粗糙度减小.进一步的人脐静脉内皮细胞(HUVEC)种植实验表明表面粗糙度的变化对内皮细胞的贴附、生长与增殖有很大的影响.     

外加磁场对磁控溅射靶利用率的影响

通过在基片上直接放置一块永久磁铁来研究外加磁场对磁控溅射靶利用率的影响。实验发现，外加磁场的引入改变了靶表面附近的磁场分布，因而靶的刻蚀环的位置、宽度和深度均发生了明显的变化，靶的利用率在S—S构型和S—N构型中均比无外加磁场时要高。利用空间模拟磁场成功的解释这一实验现象。在S—S构型和S—N构型中，后靶的刻蚀深度轮廓线比较平坦，相对刻蚀深度值更大，更能有效地提高靶的利用率。     

圆平面磁控溅射靶磁场的ANSYS模拟分析

磁控溅射靶面磁感应强度的水平分布直接关系到靶材的利用率和刻蚀的均匀性.为了寻求更好的磁控靶结构参数,从而实现靶而水平磁感应强度的均匀分布,作者应用ANSYS软件对SD500型磁控溅射镀膜机的圆平面靶表面磁感应强度进行模拟,应用SHT-V型特斯拉计通过同心十字线法对实物靶表面磁感应强度进行测试,将模拟结果与测量结果进行比较,证明其模拟的准确性.进而对圆平面磁控靶的结构参数进行优化设计,得出靶与磁钢间距为3 mm、磁钢高度为15 mm、内磁柱半径为4 mm、内磁柱高度为14 mm时靶面水平磁感应强度最强、分布最均匀.在工程应用中,设计人员可以预先对靶的参数进行优化设计,使设计的磁控溅射靶更好的满足生产和科学研究的需要.     

Target profile change during magnetron sputtering

A simplified model is presented here to explain the structure of the back deposited material from a circular magnetron source. From the microstructure of the Al deposit on the dead zone of a magnetron source and by comparison with Al deposit from a vapour source, at large angle (i.e. >45°), a proposal is made as to formation of a virtual source in the cathode-substrate gap. Experiments were carried out to show how the height of this virtual source from the magnetron target varies with pressure. Some general results have then been deduced from the shape and microstructure of back deposit on the sputtering source at various pressures.     

磁控溅射靶的磁路设计

磁控溅射是现代最重要的镀膜方法之一，具有简单，控制工艺参数精确和成膜质量好等特点。然而也有靶材利用率低、成膜速率低和离化率低等缺点。研究表明磁场结构对上述问题有重要影响，本文介绍了一种磁控溅射靶磁路优化设计方案。并对改进的磁场结构和一般的磁场结构进行了分析比较，并给出了实验结果。     

Effect of the target bias voltage during off-pulse period on the impulse magnetron sputtering

With a high-power impulse magnetron sputtering (HiPIMS) apparatus, it has been studied how the target bias voltage during the off-pulse period affects the stability of the generated plasma. We have prepared an electrical pulse power source which can control the target voltage during the pulse off period, in addition to the pulse voltage, repetition frequency and a duty ratio of the pulse. Time-resolved current-voltage characteristic was monitored by an oscilloscope, and plasma generation behavior was elucidated. With titanium target and at Ar gas pressures of 0.6–5 Pa, pulse-off bias voltage was changed between −300 and +100 V, and the I-V characteristics were recorded. On increasing the negative bias voltage, the time at which the target current began to rise was gradually delayed. And at a certain voltage, the delay suddenly disappeared. This voltage was found to be the sustain voltage of the dc discharge in the same condition. Applying positive bias voltage resulted in a much longer delay. These results suggest that the minimal discharge during the pulse-off period helps the initiation of high-density plasma, while the bias voltage which can not maintain the plasma contrarily hampers it.     

Effect of the target bias voltage during off-pulse period on the impulse magnetron sputtering

With a high-power impulse magnetron sputtering (HiPIMS) apparatus, it has been studied how the target bias voltage during the off-pulse period affects the stability of the generated plasma. We have prepared an electrical pulse power source which can control the target voltage during the pulse off period, in addition to the pulse voltage, repetition frequency and a duty ratio of the pulse. Time-resolved current-voltage characteristic was monitored by an oscilloscope, and plasma generation behavior was elucidated. With titanium target and at Ar gas pressures of 0.6-5 Pa, pulse-off bias voltage was changed between −300 and +100 V, and the I-V characteristics were recorded. On increasing the negative bias voltage, the time at which the target current began to rise was gradually delayed. And at a certain voltage, the delay suddenly disappeared. This voltage was found to be the sustain voltage of the dc discharge in the same condition. Applying positive bias voltage resulted in a much longer delay. These results suggest that the minimal discharge during the pulse-off period helps the initiation of high-density plasma, while the bias voltage which can not maintain the plasma contrarily hampers it.     

Ag纳米粒子磁控溅射制备及其热稳定性研究

利用磁控溅射在玻璃衬底上制备Ag纳米粒子及其氧化物（AgOx）薄膜，通过高温退火实验，研究银及AgOx薄膜的热稳定特性。采用x射线衍射分析薄膜的晶相结构，采用UV-Vis分光光度计测定薄膜的吸收光谱。结果表明：Ag纳米薄膜在450nm附近出现特征吸收峰，200℃退火后，峰位蓝移，400℃退火后，吸收峰显著减弱，表明Ag纳米粒子在退火过程中发生了蒸发；AgOx薄膜在200℃下退火后，出现Ag纳米粒子特征吸收峰，表明AgOx的热分解，400℃退火同样导致Ag纳米粒子的蒸发。     

磁控溅射镀膜设备中靶的优化设计

磁控溅射已发展为工业镀膜生产中最主要的技术之一。对在镀膜批量生产中普遍存在的靶材利用率、溅射速率和沉积速率低以及溅射过程不稳定等突出问题，固然可用优化电源设计和调整工艺参数等加以改善，但根本的问题在于整个系统，特别是靶的优化设计。本文简要评述了已有靶的典型设计及其特点；对靶分析和设计的通行方法，包括电磁场有限元、等离子体粒子模型及流体模型、以及设计过程中其它一些需要注意的问题作了讨论。鉴于国内目前在靶的分析设计方面与国际先进水平之间还存在着比较大的差距，希望能够引起有关方面的重视。     

Numerical analysis of geometry effects for target re-deposition during low pressure hollow cathode magnetron sputtering

During low pressure ionized metal physical vapor deposition (PVD) of Cu seed layer for microprocessor interconnects, the re-deposited Cu film on the hollow cathode magnetron (HCM) target may fall off and damage the Cu film on the wafer. An analytical view factor model based on the analogy between metal sputtering and diffuse thermal radiation was used to obtain re-deposition profiles for HCM targets in low pressure (below 0.1 Pa) Cu ionized PVD. The model predictions indicate that there is an inherent non-uniformity in the re-deposition profile even for uniform sputtering over the entire HCM target. The predicted re-deposition profile agrees with experimental observations. Subsequent target redesign studies found that the non-uniformity in the re-deposition profile could be mitigated by using a conical sidewall between the top disk and the cylindrical sidewall or reducing the length of the cylindrical sidewall.     

旋转圆柱靶溅射沉积产额分布

采用数值计算模型,计算了旋转圆柱靶溅射产额分布。数值计算中假设从靶溅射出来的粒子服从余弦函数定律。计算得到的单靶溅射产额分布和Al靶在Ar气压0.4Pa测量得到的实验值基本相同。同时计算了孪生旋转圆柱靶的溅射产额分别与靶基距、靶间距,以及靶旋转角度的相关性。